Thermal conductivity measurement of insulating innovative building materials by hot plate and heat flow meter devices: A Round Robin Test

The characterization of thermal insulation properties of construction materials represents a fundamental step on the building insulation assessment. In recent years innovative materials have been introduced in the market to fulfill the continuously growing requirements of energy saving and sustainability, and their performance is not so reliable and mature as it happens for traditional insulators. The work presents a Round Robin Test realised among six European laboratories hosting hot plates devices to measure the thermal conductivity of four different materials: aerogel, vacuum insulation panels, polystyrene and birch wood fibre insulation boards. After the definition of the common measurement protocol, the tests campaign was executed and the results were checked with a consistency analysis. Data showed that the hot plate apparatuses result suitable for the measurement of the tested innovative materials, both in terms of absolute values retrieved and repeatability. The reproducibility is satisfactory as well, except for vacuum insulation panels, the most insulating samples, which present values of standard deviations quite high, at least in relative terms, so showing that the thermal properties of high performance materials must be assessed with particular care.